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Biomedical subjects

R M Davis

Publications and source records attributed to R M Davis.

At least 109 records · Page 6Linked to original sources
PubMed1988

Health education on the six-o'clock news. Motivating television coverage of news in medicine.

Prepackaged video news releases are being increasingly used to motivate television stations to cover stories in medicine and public health in their news programs. On Feb 26, 1987, the Office on Smoking and Health, US Department of Health and Human Services, distributed a prepackaged video news release to television stations across the country, calling attention to the new health warnings required on smokeless tobacco packages and advertisements. The video was sent by satellite as well as by overnight mail to selected stations. To assess the use of the video, we surveyed 76 stations that had been targeted by special intervention. These stations were in major metropolitan areas in states with a higher prevalence of smokeless tobacco use. Seventeen (22.4%) of the stations aired the story using our video during the six days following the satellite feed, reaching an estimated 2.8 million households. Another 20 stations reported that they were holding the video for use in the near future or for file footage. We conclude that the distribution of prepackaged video news stories can be an effective, relatively inexpensive technique to communicate health information to a large audience.

Health Education↗
PubMed1988

Isolation and characterization of a basic carboxypeptidase from human seminal plasma.

A carboxypeptidase which cleaves the C-terminal arginine or lysine from peptides was purified by a two-step procedure; gel filtration on Sephacryl S-300 and affinity chromatography on arginine-Sepharose. The activity increased 280% after the first step, indicating the removal of an inhibitor from the crude starting material. The activity in the crude seminal plasma eluted from the Sephacryl S-300 column with an apparent Mr 98,000 and after purification with an Mr 67,000, indicating that it binds to another protein in the crude seminal plasma. When analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, a single band at Mr 53,000 was seen which was converted to two smaller bands (Mr 32,000 and/or 26,000) after reduction. The seminal plasma carboxypeptidase has a neutral pH optimum, is inhibited by o-phenanthroline and by the inhibitor of carboxypeptidase B-type enzymes, 2-mercaptomethyl-3-guanidinoethylthiopropanoic acid, and can be activated by cobalt. The purified enzyme has a high specific activity (67.8 mumol/min/mg) with the ester substrate benzoyl (Bz)-Gly-argininic acid and readily cleaves Bz-Ala-Lys, Bz-Gly-Arg, and Bz-Gly-Lys. It also hydrolyzes biologically active peptides such as bradykinin (Km = 6 microM, kcat = 43 min-1), Arg6-Met5-enkephalin (Km = 103 microM, kcat = 438 min-1), and Lys6-Met5-enkephalin (Km = 848 microM, kcat = 449 min-1). The seminal plasma carboxypeptidase did not cross-react with antiserum to human plasma carboxypeptidase N; other properties distinguish it from the blood plasma enzyme as well as from pancreatic carboxypeptidase B and granular, acid carboxypeptidase H (enkephalin convertase). The carboxypeptidase could be involved in the control of fertility by activating or inactivating peptide hormones in the seminal plasma. In addition it could contribute to the degradation of basic proteins during semen liquefaction.

Carboxypeptidases↗
PubMed1988

Nylon suture toxicity after cataract surgery.

A cluster of symptoms and signs that appear to be related to wound closure developed in 10 of 105 consecutive patients (9.5%) who underwent uncomplicated planned extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens (PC IOL) implants. These signs and symptoms included foreign body sensation, conjunctival injection and infiltrates localized to the scleral wound, and scleral excavation underlying the running 10-0 nylon suture possibly resulting from localized scleral edema. The clinical presentation ranged from 1 to 6 weeks. Conjunctival stains demonstrated eosinophils and polymorphonuclear leukocytes in some cases. Gram stains, conjunctival cultures, and results of suture toxicology studies were negative. The authors believe that these findings represent a previously unreported complication after ECCE: acute inflammation primarily localized to the conjunctiva and sclera adjacent to the cataract wound. The etiology of this postoperative complication is yet to be determined.

Cataract Extraction↗
PubMed1987

Are physicians advising smokers to quit? The patient's perspective.

Physicians can play an important role in smoking cessation because they have frequent contact with smokers and because most smokers believe that a physician's advice is important in the decision to quit. Therefore, to determine smokers' perceptions of physician involvement in smoking cessation, we analyzed aggregate data from two random statewide surveys of 5875 Michigan adults. Of smokers who had seen a physician in the previous year, only 44% reported that they had ever been told to quit smoking by a physician. Young male smokers were the least likely (30%) to have been told to quit. Smokers who were hypertensive, obese, diabetic, sedentary, or users of oral contraceptives were no more likely to have been told to quit than smokers without these additional cardiovascular risks. Conversely, smokers who had survived a myocardial infarction or stroke were more likely to have been told to quit than smokers who had not suffered these events (73% vs 43%). Most smokers do not perceive physicians to be even minimally involved in their efforts to quit. Physicians need to increase their efforts in counseling smokers to quit before smoking-related diseases result, especially for smokers with additional risk factors for cardiovascular disease.

Adolescent↗
PubMed1987

Current trends in cigarette advertising and marketing.

Because the nation's health is so greatly influenced by cigarette smoking, this report examines current trends in cigarette advertising and marketing. According to the Federal Trade Commission, total cigarette advertising and promotional expenditures reached $2.1 billion in 1984. From 1974 through 1984, total expenditures increased approximately sevenfold, or threefold after adjustment according to the consumer price index. In 1985, cigarette advertising expenditures accounted for 22.3 percent, 7.1 percent, and 0.8 percent of total advertising expenditures in outdoor media, magazines, and newspapers, respectively. When all products and services were ranked according to national advertising expenditures, cigarettes were first in the outdoor media, second in magazines, and third in newspapers. The proportion of total cigarette advertising and promotional expenditures devoted to promotional activities has increased steadily, from 25.5 percent in 1975 to 47.6 percent in 1984. The proportion of expenditures for cigarettes yielding 15 mg or less of "tar" has increased substantially and has consistently exceeded the domestic market share of these cigarettes. The fastest growing markets are discounted cigarettes and brands containing 25 cigarettes per pack. Several advertising campaigns have targeted women, minorities, and blue-collar workers. The study of these marketing trends should assist health officials in identifying and predicting patterns of cigarette use and in developing health promotion programs that counteract the influence of advertising by incorporating similar, effective techniques.

Advertising↗
PubMed1987

Acanthamoeba keratitis and infectious crystalline keratopathy.

Two cases of Acanthamoeba keratitis and infectious crystalline keratopathy, occurring simultaneously, are presented. Three and 12 months after initiating topical corticosteroid therapy in cases 1 and 2, respectively, alpha-hemolytic Streptococcus viridans was cultured from each cornea. Topical corticosteroid therapy was initiated for the treatment of an annular stromal opacity, presumably secondary to herpes simplex keratitis. Acanthamoeba was identified in culture following penetrating keratoplasty in case 1, and Acanthamoeba polyphaga, Acanthamoeba rhysodes, and Acanthamoeba castellanii were identified using indirect fluorescent antibody staining in case 2. Histopathologic examination and electron microscopy demonstrated sheets of cocci within stromal lamellae characteristic of infectious crystalline keratopathy and double-walled encysted organisms typical of Acanthamoeba. These case reports alert one to the possibility of developing bacterial keratitis, such as infectious crystalline keratopathy, following the use of topical corticosteroids for the treatment of Acanthamoeba keratitis.

Adrenal Cortex Hormones↗
PubMed1987

Frequent alterations of specific reiterated DNA sequence abundances in human cancer.

An in-gel renaturation method allows the visualization, quantitation, and initial characterization of reiterated DNA restriction fragments (RRFs) without prior possession of their probes. Using this method we analyzed EcoRI restricted DNAs from ten human tumors, paired normal tissues from these patients, ten unpaired tumors, and 26 noncancer patients. Frequent qualitative and quantitative differences in the relative radioactive intensities of all or specific RRFs in the DNA from different individuals have been observed. However, we also report frequent two- to ten-fold alterations in the relative radioactive intensities of several specific RRFs in tumor-control analyses of DNA from the same individual. A 0.65-kb alphoid-like DNA RRF was decreased in six tumors and increased in none. Moreover, a new 1.55-kb RRF was observed in two colon cancer DNAs. Several new RRFs, suggestive of gene amplification, were detected in a neuroblastoma, two of which were also seen in a glioma. These data support frequent qualitative and quantitative alterations of specific reiterated DNA sequences in human cancer when compared with paired controls. This approach will allow the future characterization of specific DNA sequences whose patterns of altered reiteration suggest a role in the emergence of specific malignancies.

DNA, Neoplasm↗
PubMed1987

A persistent outbreak of measles despite appropriate prevention and control measures.

From January 4 to May 13, 1985, an outbreak of 137 cases of measles occurred in Montana and persisted for 12 generations of spread. A total of 114 cases occurred on the Blackfeet Indian reservation in northwest Montana. Of the 137 cases, 82 (59.9%) were in school-aged children (aged 5-19 years). Of the 114 cases on the reservation, 108 (94.7%) were classified as programmatically nonpreventable. A total of 64 (82.1%) of the 78 patients on the reservation who were born after 1956 and were above the recommended age at vaccination had a history of adequate measles vaccination. Additionally, an audit of immunization records at the schools in Browning, Montana, where most of the cases occurred, showed that 98.7% of students were appropriately vaccinated. A retrospective cohort study in the Browning schools failed to identify age at vaccination or time since vaccination as significant risk factors for vaccine failure. Overall vaccine efficacy was 96.9% (95% confidence interval = 89.5-98.2%). None of 80 Browning students who were vaccinated at less than 12 months of age and revaccinated at 15 months of age or older became infected. A case-control study showed a significant association between attendance at Browning basketball games and infection early in the outbreak. This outbreak suggests that measles transmission may persist in some settings despite appropriate implementation of the current measles elimination strategy.

Adolescent↗
PubMed1987

A cost-effectiveness analysis of measles outbreak control strategies.

This study compares the cost-effectiveness of six vaccination strategies during a measles outbreak: vaccination of all susceptibles 15 months of age or older and born after 1956 (the current routine strategy); lowering the recommended age at vaccination from 15 to 12 months (plus current routine strategy); lowering the recommended age at vaccination to six months (plus current routine strategy); revaccination of those vaccinated at 12-14 months of age (plus current routine strategy); vaccination of all students in school regardless of immune status; and vaccination of all residents 15 months to 28 years of age in the community regardless of immune status. The analysis is based on the hypothetical, early application of these strategies to a 1985 measles outbreak in Montana, which occurred despite appropriate application of current prevention and control recommendations. Although the results are applicable only to this particular outbreak, this analysis provides an approach which can be used in other settings to assess measles outbreak control strategies. Similar studies would need to be performed in a variety of settings to determine the most cost-effective measles outbreak control strategies overall.

Child↗
PubMed1987

Measles hospitalizations, United States, 1977-84: comparison with national surveillance data.

Trends in measles discharges from hospitals participating in the Commission on Professional and Hospital Activities, Professional Activities Study (CPHA-PAS) from 1977 to 1984 reflected the rapid decline in measles morbidity indicated by national surveillance data with an 88 per cent decrease in hospitalizations and a 95 per cent decrease in reported cases from 1977 to 1984. Overall trends in number, age, and seasonal distribution were also generally similar. Thirty-four per cent of the hospitalizations listed respiratory complications, 8.5 per cent otitis media, and 3.4 per cent neurologic complications.

Adolescent↗
PubMed1987

An anterior limbal approach to vitrectomy for the surgical management of infectious endophthalmitis.

We present two cases illustrating a surgical approach to the diagnosis and treatment of infectious endophthalmitis following extracapsular cataract extraction with insertion of a posterior chamber lens. In both cases, a vitrectomy was initiated through a limbal approach after clearing the anterior chamber, thus allowing improved visualization of the vitreous cavity. The vitrectomy probe was then passed through a peripheral iridotomy, the peripheral posterior capsule and/or zonules, and into the anterior vitreous. The peripheral iridotomy allowed access to the vitreous cavity for an anterior vitrectomy. The entire anterior chamber and vitreous aspirate was then analyzed for culture and sensitivity. This technique minimizes the risks of pars plana vitrectomy for endophthalmitis by improving visualization and possibly decreasing the risk of retinal detachment.

Cataract Extraction↗
PubMed1987

Subjective comparison of office perimetry.

The Fieldmaster 50 and the Dicon AP2000 are automated perimeters which perform threshold static testing. In this study, 50 patients and 10 perimetrists determined their preference after being randomly tested by each automated perimeter. Subjects responded to a series of questions comparing the perimeters. The Fieldmaster 50 automated perimeter was preferred for most of the question categories.

Evaluation Studies as Topic↗